Toronto, December 12, 2019 – O3 Mining Inc. (TSX.V: OIII) (“O3 Mining” or the “Corporation”) is pleased to provide new results from the ongoing drilling program on the Alpha property, located 5 kilometres (km) southeast of Val D’Or, Quebec. The area includes the claims under option from Golden Valley Mines Ltd. (Centremaque), of which O3 Mining has the option to acquire 80% interest.

Current drilling is focused on the Cadillac Larder Lake Fault corridor, specifically Epsilon and Pontiac East zones, (Bulldog West Extension zone (Press Release October 21, 2019) is renamed Pontiac East zone) within the Alpha property. The Epsilon and Pontiac East zones are on each side of the sheared ultramafic volcanics of the Piche Group. Follow up drilling at Bulldog, located 1.5 km east, is pending freeze-up conditions to allow access.

New analytical results include 9.3 g/t Au over 6.0 metres, including 25.7 g/t Au over 1.9 metres in

CAX-19-016. O3 Mining President and Chief Executive Officer, Jose Vizquerra Benavides, commented: “The drilling campaign on the Alpha property has significantly expanded the Epsilon zone, now being traced over a 1.5 km strike and opened laterally, as well as continue to confirm mineralized intercepts within the Pontiac sediments. This new zone opens a possibility to a mineralized envelope of significant width.”

Table 1: Drill Hole Intercepts (only intercepts above 5 g/t Au * m are reported)

Table 2: Drill Hole Details

Mineralization in CAX-19-016, in the Epsilon zone, is hosted within sheared sericitized and carbonatized graywackes and tuffs with quartz tourmaline carbonate veins. There is 2% arsenopyrite and trace pyrite within veins or disseminated in the tourmalinized host-rock. Within this larger altered zone, there are smokey-quartz veins associated with visible gold and arsenopyrite. These low angle smokey-quartz veins are typical of the Orenada Zone 4 type mineralization, located 1.5 km to the east.

The Pontiac East zone is characterized by albitized, carbonatized and silicified sediments of the Pontiac Group, containing quartz-carbonate veinlets, disseminated pyrite – arsenopyrite mineralization and visible gold locally.

Qualified Person

The scientific and technical content of this news release has been reviewed, prepared and approved by Mr. Sebastien Vigneau, P.Geo. (OGQ #993), Exploration Manager, who is a “qualified person” as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”).

Quality Control and Reporting Protocols

True width determination is currently unknown but is estimated at 65-80% of the reported core length interval for the zones. Assays are uncut except where indicated. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Half-core samples are shipped to Agat laboratory in Val D’Or, Quebec and Mississauga, Ontario for assaying. The core is crushed to 75% passing -2 mm (10 mesh), a 250 g split of this material is pulverized to 85% passing 75 microns (200 mesh) and 50 g is analyzed by Fire Assay (FA) with an Atomic Absorption Spectrometry (AAS) finish. Samples assaying >10.0 g/t Au are re-analyzed with a gravimetric finish using a 50 g charge. Commercial certified standard material and blanks are systematically inserted by O3 Mining’s geologists into the sample chain after every 18 core samples as part of the QA/QC program. Third-party assays are submitted to other designated laboratories for 5% of all samples. Drill program design, Quality Assurance/Quality Control (“QA/QC”) and interpretation of results is performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices.

About O3 Mining Inc.

O3 Mining is an emerging consolidator of exploration properties in prospective gold camps in Canada – focused on projects in Quebec and Ontario – with a goal of becoming a multi-million ounce, high-growth company. The Corporation’s goal is to become one of the premier gold exploration companies in Canada.

O3 Mining is well-capitalized and holds a 100% interest in a number of properties in Quebec (435,000 hectares) and Ontario (25,000 hectares). O3 Mining controls 61,000 hectares in Val D’Or and over 50 kilometres of strike length of the Cadillac Larder Lake Faut. The Corporation’s projects host resources of 2,066,154 gold ounces of measured and indicated resources at 1.40 g/t Au and 1,059,057 gold ounces of inferred resources at 2.95 g/t Au in Val D’Or area, and also holds the Garrison project in Ontario with over 1,570,000 gold ounces of measured and indicated resources at 1.12 g/t Au. O3 Mining also has a portfolio of assets in the James Bay and Chibougamau regions of Quebec and in the Hemlo district in Ontario.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.

For further information on O3 Mining, please contact:

José Vizquerra Benavides

President, CEO and Director

416 848 9504